All Xperia P users will get a notification when the upgrade is ready, but direct availability in the phone may vary across different markets and carriers.

For Xperia U, Xperia go and Xperia sola users - if you've already upgraded to ICS, you'll receive a notification in your phone and be able to download it over-the-air. For those guys on Gingerbread, you?ll need to plug in and upgrade using PC Companion or Bridge for Mac.